Field of the Invention
The invention relates to a drive train control system for a motor vehicle, by which the position of the accelerator pedal is interpreted as a wheel torque or transmission output torque desired by the driver and used for calculating desired values for the engine and transmission of the motor vehicle.
Prior art control systems for the engine, for the transmission, and for the secondary assemblies of a motor vehicle operate largely independently; that is, they establish the operating point and operating mode of the controlled assembly largely independently of one another. Means are also available for communication among the various components of the drive train of a motor vehicle, for instance in the form of a CAN bus or the like, but these means are predominantly used only for exchanging sensor data in the course of multiple utilization. Moreover, the control systems affect one another by means of communication in certain operations, for instance to make for smoother shifting by reducing the engine torque upon a change of transmission ratio in the transmission.
Other examples are engine drag torque control during braking and braking intervention or torque reduction if drive slip arises in the traction control context. A system for linking together systems in the automobile has become known heretofore that seeks an integrated drive train control system for a motor vehicle by means of which the position of the accelerator pedal is interpreted as a wheel torque desired by the driver and used for calculating desired values for the engine and transmission of the motor vehicle (F & M 101 (1993) 3, pp. 87-90). The goal of the overriding optimization, proposed in this publication, of the parts of the system embodied by the engine control unit, electronic accelerator pedal and transmission control unit, is to reduce fuel consumption and improve the drivability, in particular with regard to the spontaneous reaction to movements of the accelerator pedal.